A 25-year-old man travelling in a car died after the vehicle rammed into the divider on Diamond Harbour Road early on Monday, police said.

Rahul Das, the victim, was a resident of Jaigirghat Road in Thakurpukur. Sumanta Mondal, 26, who was at the wheel, is in a critical condition at the Calcutta National Medical College and Hospital, the police said.

The two others in the car — Santu Mondal, 27, and Subhankar Haldar, 25 — have been admitted to MR Bangur Hospital.

“They were returning from a party. Santu is Sumanta’s brother. He and Das were in the back seat,” an officer of Thakurpukur police station said. “The vehicle hit the divider at high speed and overturned.”

Initially, a case of rash and negligent driving was started against the driver. After one of the occupants died, the section on causing death by negligence has been slapped on Sumanta.

The vehicle has been seized. It will undergo a mechanical test, the police said.